1. Field of the Invention
The present invention relates to a diagnostic imaging apparatus and method for limbs, particularly the hand, by means of nuclear magnetic resonance, which method comprises the steps of positioning the hand in a detection volume of a nuclear magnetic resonance imaging apparatus, inside a dedicated coil, of selecting the section or sections of the hand or wrist of which the image has to be detected and of carrying out the image detection by means of nuclear magnetic resonance.
2. Discussion of Related Art
At present it has been found that in the evaluation of rheumatoid arthritis the images detected by nuclear magnetic resonance allow one to visualize pathological damages caused by rheumatoid arthritis in a better way than radiograph images, particularly the so called erosion. However these damages are at an advanced phase of the pathology. Recent analysis have shown that due to the image detection with nuclear magnetic resonance it is possible to find damages caused by rheumatoid arthritis in the initial phases of the pathology, such as the damage of soft tissues for example synovium, tendons and meniscus.
The synovial membrane is the main inflammation site in the precocious phases of rheumatoid arthritis. During these phases the inflammatory action involves an increase of the vascularization that can be highlighted in the nuclear magnetic resonance images by means of proper contrast agents, such as Gadolinium-di ethylentriamine of pentacetic acid (Gd-DTPA). Recording time sequences of nuclear magnetic resonance images of the synovial membrane with the above contrast agents shows changes of the signal intensity as a function of time that can be considered as indicators of the synovial inflammation and of the pathological activity. This has been shown by analysis regarding the intensity changes of MRI signal in the synovial membrane of the wrist.